Lately, an increasing number of image processing inspection apparatuses have been introduced as production equipment into factories and the like for the purpose of correctly, speedily and automatically executing a variety of visual inspections which have relied on the human visual sense. For example, image processing inspection apparatuses are disclosed in Japanese Patent Laid-open Publication Nos. 7-234934 and 8-043053.
FIG. 15 is a view for explaining a state in which products are inspected by an image processing inspection apparatus. As shown in FIG. 15, the image processing inspection apparatus A' is connected to a TV camera 1 for grabbing an image, a display monitor 5 for displaying the image or the like of the product on the way to inspection and a keypad 7 for performing operations such as various setting operations. The image processing inspection apparatus A' grabs the image of a product (referred to as a target hereinafter) t which is on the way to production and is treated as an object to be measured while being conveyed on a production line in the form of an image signal from the TV camera 1 in accordance with a timing at which an external trigger input from a sensor 3 or the like is inputted. Subsequently, the image processing inspection apparatus A' executes various image processing operations such as position correction, area measurement and barycentric position calculation on the grabbed image, executes numerical calculations with the obtained various results, executes logical calculations for a go/no-go check with the obtained values and then outputs the result. The image processing inspection apparatus A' generally executes the above series of calculation and outputting processes.
Normally, a time from the start of grabbing the image to the completion of all the inspection processes in readiness for the process of grabbing the next image is generally called the inspection time.
The prior art image processing inspection apparatus A' has executed the process of grabbing image data from the TV camera 1 into an image data memory for image grabbing and continuously executed a series of calculation and outputting processes after the completion of the image grabbing. Furthermore, the prior art image processing inspection apparatus has required a specified time for image grabbing, e.g., 33.3 ms in the case of frame image grabbing or 16.7 ms in the case of field image grabbing. In the case where the processing is executed continuously as described above, the inspection time has not been allowed to be reduced further than the time of "image data grabbing time" plus "image processing time plus calculation and output processing time" even when a tact for the inspection is short (i.e., when the inspection must be completed in a short time).
FIG. 16 shows a schematic diagram of hardware of the prior art image processing inspection apparatus. The image processing inspection apparatus A' is comprised of an image data memory 32, a display use output circuit 33, an image processing use circuit 37 and selection switch circuits 34 and 36. In this apparatus, image data from the TV camera 1 is grabbed into the image data memory 32 and simultaneously inputted to the display use output circuit 33 via the selection switch circuit 34, where separately set data from a graphic data memory (not shown) is superimposed on the above data at need and the resulting data is outputted to a display means such as the display monitor 5. The image data grabbed in the image data memory 32 is outputted to the image processing use circuit 37 via the selection switch circuit 36, and the image processing use circuit 37 executes various measurements of the position, shape and so forth of the target based on this image data so as to execute the go/no-go check of the target. Further, the image data grabbed in the image data memory 32 can be outputted to the display use output circuit 33 via the selection switch circuits 36 and 34 and displayed on the display monitor 5.
Furthermore, the image data from the TV camera 1 is required to be displayed as, for example, binarized in the inspection process. In this case, as shown in FIG. 17, the image processing inspection apparatus A' is required to have an arrangement in which a binarizing circuit 39 for binarizing the image data from the TV camera 1 is provided for allowing the selection between the image that is binarized and the image that is not binarized by means of a selection switch circuit 38 or prepare a means for converting the image data grabbed in the image data memory 32 into binarized data and thereafter outputting the resulting data to the display output circuit 33.
As described above, the prior art image processing inspection apparatus has the problem that the inspection time cannot be reduced and the problem that a special circuit is necessary in the case where the image is displayed as processed, e.g., in the case where the grabbed image is displayed as binarized.
The present invention has been developed in view of the above points and it has an object to provide an image processing inspection apparatus capable of reducing the inspection time and setting a variety of inspection process and display modes with a simple construction.